The Document Foundation on Tuesday announced the availability of LibreOffice 3.5, which it described as the third major release of the open-source productivity suite derived from the OpenOffice.org codebase.

LibreOffice is backed by companies such as Red Hat and Google. The Document Foundation was formed in September 2010 by some OpenOffice.org community members after they had a falling out with Oracle, which acquired the software through the purchase of Sun Microsystems. Oracle later stopped selling a commercial version of the suite and then submitted the code to the Apache Software Foundation.

The Document Foundation overcame significant obstacles on the way to version 3.5, "the best free office suite ever," it said in an official blog post on Tuesday.

"We inherited a 15 years old code base, where features were not implemented and bugs were not solved in order to avoid creating problems, and this -- with time -- was the origin of a large technical debt," said Caol&#225;n McNamara, a Red Hat developer and co-founder of the Document Foundation, in the post. "We had two options: a conservative strategy, which would immediately please all users, leaving the code basically unchanged, and our more aggressive feature development and code renovation path, which has created some stability problems in the short term but is rapidly leading to a completely new and substantially improved free office suite."

Since the group's creation, some 30,000 "code commits" have been submitted by developers, according to the blog.

"Power users" should download and install version 3.5 now but "more conservative" users should keep using 3.4 for now, the group said. "Corporate users are strongly advised to deploy LibreOffice with the backing of professional support, from a company able to assist with migration, end user training, support and maintenance."

A list of companies certified to perform such services will be made available soon, according to the Document Foundation.

Version 3.5's new features include an English grammar checker, a filter for PostgreSQL databases and an import filter for Microsoft Visio drawings.

Along with visible improvements to the product, developers have cleaned up the code substantially and built a suite of automated tests, said Document Foundation co-founder Michael Meeks in the blog. While much work remains to be done, the software should please users who have been less than pleased with its stability, he added.

While LibreOffice appears to be maintaining momentum, OpenOffice.org development could get an added boost of activity soon. Last month, an IBM executive revealed that the company will stop developing new versions of Lotus Symphony, its own fork of the OpenOffice.org codebase, and instead focus its efforts on the Apache OpenOffice project, with the intent to offer an IBM-branded version of it.